Polyurethane has good mechanical strength and elasticity, is therefore widely used in various applications such as coating agents, molding materials, paints, and optical films, and is actively studied as materials for synthetic leathers.
Materials for the synthetic leathers are required to have surfaces with high stain resistance (particularly oilproofness). For example, one previously disclosed material for synthetic leathers with stain resistance is a composition prepared by adding a fluorine compound in a polyurethane solution (see, for example, PTL 1).
However, fluorine compounds are expensive, and it has been pointed out that some fluorine compounds influence the human body. Therefore, there is a need for development of a material that provides high stain resistance using no fluorine compound.